OPERATION METHOD OF A REAL-TIME MULTI LEVEL POSITION RECOGNITION SYSTEM OF HARBORS ENVIRONMENT BASE WHICH MEASURES A TAG OF YT THROUGH A MOBILE READER AND THE POSITION OF THE MOBILE READER OF TC THROUGH A FIXED READER WHICH IS INSTALLED AT A LIGHTING TOWER

摘要

PURPOSE: An operation method of a real-time multi level position recognition system of harbors environment base is provided to improve the success rate and the accuracy of position measurement by considering the failure of wireless communications.;CONSTITUTION: A tag which is attached to an YT(Yard Tractor) transmits a radio signal to mobile readers for measuring its own position through a blink message(S10). The mobile readers which receives the signal of the tag return an ack signal to the tag(S20,S30). The tag attached to the YT collects distance information between the mobile readers and the tag through a TWR(Two Way Ranging) technique and the mobile readers(S40). The tag measures the distance with the mobile readers using the collected distance information(S50). The tag transfers distance information data based on the measured distance information to the mobile reader in which RSS(Received Signal Strength) value is the most high(S60). The mobile reader transmits distance information data to a fixed reader(S70). The fixed reader transmits the distance information data to a position calculating engine(S80).;COPYRIGHT KIPO 2012